This invention relates to a sleepy warning system which is constantly monitoring a driver""s pulse rate and activates an alarm means if the monitored pulse rate falls below a predetermine level.
A vast percentage of automobile accidents are attributed to sleepy driving. Many attempts have been made to develop a warning device which is activated when the driver becomes sleepy. One such device is made of a yoke, a pressure sensor and a sound device, which is worn around one""s neck. The operation of the device is as following: when the driver feels sleepy, his head bents over on the yoke pressing the pressure sensor and the pressed sensor activates the sound device. However, wearing the device around the neck is very cumbersome, and placing the pressure sensor on the position where the head falls is very inconvenient.
Another inventor has tried to develop a drowsy alert system by applying a video sensor which is monitoring eyes opening. When the sensor monitors eyes closing for a couple seconds, it triggers the alert system. For many reasons, it has not been successful yet. In light of the importance of accident prevention for a vehicle, developing a reliable, convenient, and affordable sleep warning device is the prime objective of this invention.
This invention is relating to a sleepy warning apparatus which comprises a pulse sensor, a measuring device and a warning device. A pulse rate is affected by the many variables. Each individual""s pulse rate is different from one person to another. For the same person, the pulse varies depending upon how physically active the person is. The normal pulse rates for ordinary people are somewhere between 50, to 85. Another aspect to change pulse rate is the state of sleepiness.
For the most people, sleepy pulse rate is somewhere between 55, to 65. For the illustration purpose of this embodiment, when the start switch is pressed from off state, it sets threshold pulse rate to 60 (example) and stores it in a memory or a register, and starts measuring time interval for the predetermined number of pulse count, then converts this time interval to the pulse rate. Repeat this process continuously. Every newly measured pulse rate is compared to the threshold pulse rate, and if it is lower than the threshold pulse rate, it will trigger the alarm system.
The threshold pulse rate can be adjusted experimentally by INCREASE switch or DECREASE switch. Every push of these switches either increases or decreases the pulse rate by one. If the alarm is triggered while not quite sleepy, the threshold pulse rate can be decreased by pushing the DECREASE switch repeatedly, same number of times as the number to be adjusted. If the alarm feature is not triggered even if the person is sleepy, the pulse rate can be increased by pushing INCREASE switch repeatedly, same number of times as the number to be adjusted. Thus, the threshold pulse rate is determined by 2 different steps:
1) upon start switch pressed, the threshold number is set to 60 as default.
2) the threshold number can be either increased or decreased by the INCREASE switch or DECREASE switch.
If the pulse detector has not received any input pulse for 2 minutes period, the system get into sleep mode to save the battery consumption. During sleep mode, the system keeps the last held threshold number and last measured pulse rate in a memory. When the WAKEUP switch is pushed, the sleep pulse rate can be adjusted. Once the system is waked up by WAKEUP_switch, it will stay waked up as long as there is continuous pulse input. The system can be combined with a real clock function. The WAKEUP switch allows data display function, and preset threshold sleepy pulse adjustment function.
The system can be wearable on a wrist or attachable on a steering wheel of a vehicle with an additional cuff for placing a finger in it to monitor the pulse rate. The cuff includes the pulse sensor means. The system includes 4 externally activated switches, start switch, wakeup switch, increase switch, and decrease switch. Start switch turns the system off completely or turns it on to start from reset procedure. On the other hand, wakeup switch is used to wake up from the sleepy function for display function, and preset threshold sleepy pulse adjustment function.